$1,695.00
-
HKS Legamax Exhaust; Includes Center Pipe; For use with HKS Bellmouth Downpipe #33006-BF003 by HKS for the Subaru WRX STI
HKS PN# 31008-BF001
This product is designed and manufactured specifically for the Subaru WRX STI. This product includes the center pipe and is for use with the HKS bellmouth downpipe.
Reduction of secondary exhaust gas back pressure will improve response of turbocharger.
EJ engines’ common problem of knocking due to high exhaust gas pressure can be solved. Thus, it is recommended for safe performance upgrading.
![]() |
Whole front pipe will be changed from stock Φ60 to Φ75. It reduces secondary exhaust gas back pressure that is a common problem of EJ engines. |
![]() Φ75 flange. With the specified muffler, whole exhaust system will be Φ75. |
![]() Extension flange portion has smooth surface by lost wax casting. |
![]() Extension portion has HKS logo. |
BB Tune is…
“Boxer’s Balance Tune” and it is a project of HKS to analyze completely about typical problems of EJ20 engine due to its boxer engine layout. Previously, EJ20 engine had been considered as it was easy to be damaged. To find out the cause, the engine was analyzed on test bench at HKS and found out that reducing back pressure is the point to prevent knocking and the know-how changed EJ tuning in Japan. Since EJ25 has the same engine layout, reducing back pressure is effective for safe tuning.
To reduce secondary back pressure, replacement of front pipe will be required for further tuning.
If interested, please contact us at Bulletproof Automotive for more information regarding pricing, fitment, shipping costs, as well as installation recommendations.
Part #: 31008-BF001